Temperature control method and means



Dec. 29, 1936 D. G. TAYLOR 3 TEMPERATURE CONTROL METHOD AND MEANS FiledFeb; 2, 1951 n IO .46 4/ as I 5E INVEN'roR V7/////// W///////// DANIELATTORNEYS Patented Dec. 29, 1936 UNITED STATES PATENT OFFICE Daniel G.Taylor, Minneapolis Minn, assignor to Minneapolis-Honeywell RegulatorCompany, Minneapolis, Minn a corporation ot Delaware ApplicationFebruary 2, 1931, Serial No. 512,887

31 Claims.

This invention relates to methods and means for controlling heatingplants, directly in com formity to outdoor atmospheric conditions, tothe end that the proper temperature level may be maintained withindoors, even though the heat loss from the building may be increased dueto wind. Heretofore it has been common practice to attempt to maintainthe proper indoor temperature either by means of thermostatic elementslocated in the rooms, or by means of one such element located indoorsand another outdoors, with the arrangement such, for ex ample, that foreach degree of drop of outdoor temperature, the'temperature of theheating medium is raised one degree. The principal disadvantage of thissystem is that it cannot re spond to an increased heat loss due to wind.For example: Using an ordinary thermal device, such as a thermometer,located outdoors, and with a temperature of say 20 below zero, thethermometer registers that temperature whether the wind is or is notblowing. I

It is, therefore, an object of this invention to provide a thermostaticdevice for controlling the heat supply in the building, and to arrangeit to be affected by atmospheric conditions outside of the space to beheated. Such a device will accurately respond to the additional heatloss within the house, due to wind, and will also for example, tosunshine, shadow,- etc.

The present system also has the advantage of placement of the thermalcontrol means at a position where it cannot be conveniently 35 tamperedwith by the occupants of the building, or enclosed space to be heated.Moreover, where thermostats are located in any room or in any space tobe heated, the tenant may open the window, and cool the room or spacesufficiently to start the heating plant and supply heat to otherapartments or spaces when it is not needed. This latter contingencyoccurs where a. single heating plant supplies a number of apartments andwhere the thermostat in each apartment is adapted to control the heatingplant.

Objects, features and advantages of the invention will be set forth inthe description of v the drawing forming a part of this application,-and in said drawing Figure l diagrammatically illustrates oneapplication of the invention; and

Figure 2 diagrammatically illustrates the invention applied forcontrolling the temperature in a plurality of compartments in proportionto the average of the heat losses therefrom.

respondto all other temperature variations due,

The numeral i indicates the wall of any enclosed space 2 to be heated,such as a house or room. Thermal means is arranged to be affected byatmospheric conditions outside the space 2. In this instance, thethermal means includes the metal block 3, upon which a thermostaticswitch is mounted. This device is suitably protectingly housed by acasing t which, however, does not prevent proper atmospheric action uponthe metal block. For example, it does not prevent 16 moving air fromafiecting the block to cause additional heat loss therefrom.

The top of the block is provided with asockct 5 into which is fitted ametal tube 5, which tube projects upwardly beyond the block as 15 shown.Within the tube is arranged a bimetallic thermostatic element F adapted,when cooling and moving to the leit to first make electrical contactwith a binding post 8, adiustably supported by the wall of the tube 5.It will be assumed, for illustrative purposes, that the thermostaticelement 1 will make contact with the element 8 when block temperature is60 F. Associated with the bimetallic element and operable thereby is asecond contact element '10 cooperable with a binding post ll, alsoadjustably supported'in the tube wall. In this instance, the element It,or holding contact, is first to close. It may be assumed that after.

the element 10 has made contact with the binding post Ii, it will onlymove to open its circuit at a block temperature of 80.

Numeral 20 indicates the burner motor, or equivalent control device, ofa heating plant, which plant is to be controlled in conformity to 5temperature conditions at the block. An electrically operable heatingelement 2! is associated with the block. Any suitable means may beemployed for this purpose, but any electrically operable heating meansis convenient, forone reason 4 because the heat in-put can be accuratelyadjusted. This is generally inserted in a cavity of the block. The gridor heating element 2| is so placed that the thermostatic element willrespond rather to the block temperature than directly to gridtemperature. The numerals 2223 respectively indicate the hot and groundsides 01' a suitable electric power source. Connected across the line isthe primary 24 of a transformer A, the secondary of which is indicatedat 25. A relay is used for controlling the burner, the coil or whichrelay is shown at 2B. This relay controls contacts 2l28 respectively aholding contact, in circuit with elements I 0-! I, and a motor controlcontact. The contact 28 is connected by $6 conductor 29 with the hotside 22 of the line, the opposite side of the contact being connected byconductor 30 with one terminal of the motor, and the other terminal ofthe motor being connected by conductor 3! with the ground side 23 of thepower line. Obviously, when the contact 28 is closed, the motor will beenergized. Although it has not been shown, it will be understood thatthe usual apparatus for producing and maintaining flame is provided, andit will be further understood that while the motor is operating, heatwill be supplied to the indoor space or spaces to be heated. Oneelectrical heating element or coil H is connected with the conductor 3|by conductor 45. The other side of the heating element is connected byconductor H to one side of an ainmeter it, the other side of the ammeterbeing connected by conductor 43 with one terminator a variable resistorschematically indicated at opposite terminal of the resister isconnected to conductor 33 by conductor 46. The arrangement therefore, inthis instance, such that when the contact 28 is closed, the heatingelement is energized at the same time as the motor. By use of thevariable resistor, the degree of heating may be regulated, and thedegree of regulation is indicated by the ammeter.

In this case, it has been assumed that the motor is to be energized andheat is to be supplied when the temperature of the thermal element 1reaches 60 F. .To this end, the adjustable binding post or contact 8 isconnected by conductor 59 with one terminal of the relay coil 26, theother terminal of the coil being connected by conductor 5| with one sideof the secondary 25. The opposite side of the secondary is connected byconductor 52 with one terminal of the thermostatic element '1. It isobvious that when '1 makes at 8, the relay will be energized. In orderto stop the motor at a temperature of 80 F. (the assumed illustrativetemperature level), as controlled by the thermal element 1, a holdingcircult is provided, and includes a conductor 60 connecting theadjustable binding post II with the contact 27, the other side of thecontact being connected by a conductor 6| to the same terminal of therelay coil 26 to which the conductor 50 is connected. The resistor is inseries with the heating element.

The thermostat 1 is to maintain the same average temperature in theblock, as that to be maintained indoors. The heat loss from the blockincreases or decreases in direct proportion to the heat loss from thespace, the temperature of which is being controlled. It is possible bymanipulating the resistor 45 to so adjust the heat input to the blockthat the house will be maintained at a definite temperature (or that theheating plant will be operated in a definite way), no matter what thevariations in outdoor temperaturemay be. It is obvious that with a givenheat in-put to the block, a corresponding eflect will be transferred tothe thermostatic element 1. The amount of this input will remainconstant, as long as the atmospheric conditions remain the same.However, in case of wind, additional heat loss would occur which wouldresult in more quickly lowering the temperature of the thermal element 1with the result that it would more quickly make contact, with theelement9 to initiate earlier operation of the fuel supply apparatus. If,however, with that given heat input the outside temperature should rise,due to heating effects of the sun, the block would receive more outsideheat, that heat would be added to the heat supplied by the element 2|,and the thermostatic element In would more quickly move away'from theelement H and, therefore, the period of burner apparatus operation wouldbe reduced.

Thus the burner is under the sole command of an outside thermal meanswhich is adjustable. In case of a sharp drop at night, as from 60 to 50,in a comparatively short length of time, the outside thermostat startsthe heating apparatus before the house begins to cool, and thusanticipates the demand of heat by the house, inasmuch as the house ismore slowly responding to the outside temperature drop than thethermostat. Although the ho'ise may begin to slowly cool, the heat inthe heating plant is being built up so that long before the enclosurecan assume the outside temperature or be unduly cooled, the

radiators are hot enough to increase the house temperature eonformablyto the outside temperature drop.

In order to obtain the proper functioning of the present device, theaverage temperature of the block should be the same as the averagetemperature of the house. In this device, the average heat loss of theblock should be proportional to the difference between the temperatureof the block and the outside temperature. The device is readilyadjustable to obtain the desired result.

The important feature of the invention is the arrangement whereby thethermostat or equivalent device is set to maintain the same averagetemperature in the block as that to be maintained in the space to beheated, so that the heat loss from the block increases or decreasesdirectly in proportion to the heat loss from the space heated.

Figure 2 diagrammatically represents a vertical section through abuilding showing a plurality of rooms or spaces to be heated. Thesespaces are respectively indicated 90, 9|, 92, and 93. Each of thesespaces is provided with one or more radiators; each designated by thenumeral 94. These radiators have a single supply and return pipeindicated at 95, the steam to which pipe is provided by a boiler orother suitable apparatus indicated at 99. The heat is supplied by meansof burner apparatus generally designated 91, and which has the burnermotor 20 which corresponds to the motor previously described and shownin Figure l. The control system for the motor is substantially identicalwith that previously described. The resistor 45 and ammeter have beenomitted in the illustration. For clearness, the same reference lettersare used for the control systems in both figures oi the drawing. Thermalmeans is arranged as in the first case to be affected by atmosphericconditions, forexample outside the building. This thermal means ishoused by the casing 4, as previously described, and is now referred toas the control station. Within the casing is the block I, the heating,element 2|, the metal tube 6 carried by the-block, the thermostaticelement 1, the switch element Ill and the contacts 8 and I I. Thethermostatic element 1 responds to the temperature at the contodifference in-iocation or exposure), the temperatures of respectivecompartments will differ. Room may have a temperature of sixty; room 9!sixty-five, room 92 seventy-five and room 93 eighty degrees. It isobvious that this may be so, because the rooms 909l being at the top,near the roof, have greater heat losses, and rooms 92-93 may be locatedon the north side of the building so that they have certain diii'erentheat losses due, for example, to wind. An average of the temperature ofthis group of rooms gives, in this instance, a temperature of 70 whichno single compartment has. However, it is desirable to operate theheating plant so that sufficient steam is generated to maintain thisaverage temperature in each room of the group. It is evident that aproper control for the group cannot be had by a thermostat placed in anyone of the rooms, nor by a number of thermostats one in each room.

In further explanation, it should be noted that others have attempted tocontrol the heat supply so as to maintain some average temperature. Inone system, the average temperature of the various compartments istaken, for example, by placing a thermal couple in each compartment,averaging the electric current set up,.and then controlling the heatsupply according to that average. In another system, air is withdrawnfrom each of the compartments and mixed and then used to control athermostat which, in

turn, controls the heat supply. These are all expensive and intricatedevices, which are unnecessary in the present system. The controlstation 4 may be exposed to temperature outside the apartment building,and this station may be considered as another compartment, or house,which is to beheated. The weather conditions which affect the controlstation 4 also afiect the group of compartments as a whole, so that thecompartments, as a group, will have a heat loss which is proportionateto the heat loss at the station I. Having determined the proportionateheat losses of the control station and of the compartments as a group,it will be necessary to supply a proportionate amount of heat to thecompartments as a group, and to the control station. For example,suppose that the control station when maintained at an insidetemperature of 70" has a heat loss of B. t. u. per hour, and that thecompartments as a group have a loss of 5000 B. t. 11. per hour, when theaverage temperature in the compartments is 70. It will then be necessaryto supply 100 B. t. u. per hour to the control station and 5000 B. t.11. per hour to the compartments as a group. Therefore, heating means 2|will be so constructed as to deliver 100 B. t. u. per hour and theheating means 98 (20) will be so constructed as to deliver 5000 B. t. u.per hour. These examples correspond to the lowest expected outsidetemperature, and, of course, may be varied according to the conditionsunder which the apparatus is used. On fluctuation of outsidetemperature, the thermostat 1 calls for heat at intervals, and in amanner to operate the heating means 20 often enough and oversufficiently long periods to maintain the inside temperature of thecontrol station at 70. The heater 96 will be operated similarly andshould supply enough heat to maintain the average temperature of thecompartments at 70.

It is to be noted. that it is unnecessary to provide separate heatingmeans for the control station and the group of compartments because theheater might be so designed as to be capable of producing 5100 B. t. u.per hour under maximum operating conditions and 100 B. t. u. could bebypassed to the control station, by suitable proportioning of theradiation.

I claim as my invention:

1. A space to be heated, an electrically operable heating apparatus iorsupplying heat to the space, a heat sensitive means arrangedto beaffected by atmospheric conditions outside the space, and including ametallic block supporting a thermostatic switch, means for heating theblock, and circuit connections adapted to control the heating apparatusand block-heating means, conformably to the command of the thermostaticswitch and to energize both when the temperature has reached onepredetermined level and to tie-energize both when at a higher level.

2. A space to be heated, an electrically operable heating apparatus iorsupplying heat to the space, a heat sensitive means arranged to beaffected by atmospheric conditions outside the space, and including ametallic block having a thermostatic switch aiiectable thereby,electrically operable means for heating the block, and circuitconnections adapted to control the heating apparatus and block heatingmeans conformably to the command of the thermostatic switch and toenergize both when the temperature has reached one predetermined leveland to de-energize both when at a higher level, and electrical means foradjusting theelectrical in-put to the heater means.

3. A space to be heated, an electrically operable heating apparatus tosupply heat to the space, a heat sensitive means arranged to be affectedby outside temperature conditions and at greater velocity than the spaceto be heated, and including a metallic block having mounted therein athermostatic switch controlling two ad" justable contacts, means forheating the block, and circuits adapted to control the heating apparatusand block heating means conformably to the command of the thermostaticswitch and to energize both when the temperature has reached onepredetermined level and to de-energize both when at a higher level, andmeans for adjusting the electrical heat in-put to the heater means.

4. An enclosed space to be heated, heat conductive means placed so as tobe affected by atmospheric conditions outside the space, thermostaticmeans affectable by the heat-conductive means, an apparatus for heatingthe space, means for heating said heat-conductive means, and meansadapting the thermostatic means to control the heating apparatus andheating means to cause the same to supply heat when the ther-- mostaticmeans is at one temperature level and to interrupt heat supply when saidthermostatic nieans reaches another temperature level.

5. An enclosed space to be heated, heat conductive means placed so as tobe affected by atmospheric conditions outside the space, thermostaticmeans afiectable by the heat conductive means, an apparatus for heatingthe space, means for heating said heat conductive means, and meansadapting the thermostatic means to control the heating apparatus andheating means to cause said apparatus and means to supply heat when theheat conductive means is at one temperature level and cause saidapparatus and means to discontinue heat supply when said heat conduc-'tive means is at another higher temperature level.

6. An enclosed space to be heated-and adapted to be affected byatmospheric conditions, a metallic block adapted to be affected byatmospheric conditions outside the space, a thermostatic switch adaptedto be affected by block temperatures, a heating apparatus for heatingthe space, means for heating the block, and means controllable by saidswitch to operate the heating apparatus and heating means when thetemperature has fallen a predetermined degree, and to render the sameinoperative when the temperature of the thermostatic switch has risen toa predetermined level.

'7. A device of the class described including a plurality ofcompartments to be heated, a control station of substantial mass outsideof the compartments and of a volume extremely less than any compartment,and subject to meteorological conditions which also aifect thecompartments as a group, heating means for supplying heat to thecompartments as a group and to the control station in proportion totheir relative heat losses, and a control device responsive to thetemperature of the control station for controlling the operation of saidheating means.

8. A system of control including an enclosed space to be heated, a blockof metal exposed to atmospheric conditions outside the space, includingwind, a heater for the block, a thermostat which is principallyresponsive to the temperature of the block, and means controlled by thethermostat for controlling the supply of heat to the space and to theheater for causing the average temperature of the thermostat to equalsubstantially the average temperature of the space.

9. In a device of the class described, the combination with a mass, ofmeans for heating the mass at a definite rate, means for changing therate of heating the mass, a building, means for heating the building,automatic means for simultaneously turning on the mass heating and thebuilding heating means at a predetermined temperature of the mass, andautomatic means for simultaneously turning off the mass heating meansand the building heating means at a predetermined higher temperature ofthe mass.

10. In a device of the class described, the combination with a building,of a mass located outside of the building, means for heating thebuilding, means for heating the mass, and a thermostatic elementactuated by the temperature of the mass for respectively turning on thetwo heating means and turning off the two heating means at two differenttemperatures of the mass.

11. The method for regulating the temperature of a building by turningoii and on the heat energy to the building at diiTerent intervalsdepending upon the atmospheric conditions outside of the building, saidmethod consisting in heating a mass located outside of the building to apredetermined high temperature, allowing the mass to cool to apredetermined low temperature, reheating the mass to the predeterminedhigh temperature, continuing this cycle indefinitely, keeping a heatsupply to the building turned on during each of the periods required toheat the mass from the predetermined low temperature to thepredetermined high temperature, and keeping the heat supply to thebuilding turned on during each of the periods required for the mass tocool from the predetermined high temperature to the predetermined lowtemperature.

12. An electrical control system comprising a device for controlling thesupply of heat to a building, a thermostat for controlling the device,said thermostat being located outside the building in casing means whichsimulates said building in radiation characteristics and which issubjected to similar conditions of wind and temperature, auxiliaryheating means associated with said thermostat is said casing means, andcircuit connections interconnecting said thermostat with said device andheating means, whereby heat is supplied to the thermostat while heat issupplied to said building, and loading means for automatically delayingthe operation of said thermostat when heat is turned on after aprolonged period of cold.

13. An electrical control system comprising a device for controlling thesupply oi heat to a building, a thermostat for controlling the device,said thermostat being located outside the building in casing means whichsimulates said building in radiation characteristics and which issubjected to similar conditions of wind and sunshine, auxiliary heatingmeans associated with said thermostat in said casing means, and circuitconnections interconnecting said thermostat with said device and heatingmeans, whereby heat is supplied to the thermostat while heat is suppliedto said building, and means in said building for regulating the rate ofheat supply by said auxiliary heating means to said casing means.

14. An electrical control system comprising a device for controlling thesupply of heat to a building, a thermostat for controlling the device,said thermostat being located outside the building in casing means whichsimulates said building in radiation characteristics and which issubjected to similar conditions of wind and temperature, auxiliaryheating means associated with said thermostat in said casing means, andcircuit connections interconnecting said thermostat with said device andheating means, whereby heat is supplied to the thermostat while heat issupplied to said building, loading means for automatically delaying theoperation of said thermostat when heat is turned on after a prolongedperiod of cold, and means in said building for regulating the rate ofheat supply by said auxiliary heating means to said casing means.

15. In a system of the class described, a building to be conditioned, acontrol housing outside of said building, said building and said controlhousing being afiected by variations in outside atmospheric conditions,conditioning means for,

changing the temperature in said building, conditioning means forchanging the temperature in said control housing, the capacities of saidconditioning means being so proportioned that equal operations thereofwill maintain predetermined related temperatures in said building andsaid control housing, and means responsive to variations in temperaturein said control housing for controlling the conditioning means for saidcontrol housing to maintain a predetermined tem perature therein, saidmeans also controlling said conditioning means for said building wherebya predetermined temperature is maintained'in said building.

16. An electrical control system comprising a device for controlling thesupply of heat to a building, a thermostat for controlling the device,said thermostat being located outside the building in casing means whichsimulates said building in radiation characteristics and which issubjected to similar conditions of weather and sunshne, auxiliaryheating means associated with said thermostat in said casing means, andcircuit. connections interconnecting said thermostat with said deviceand heating means, whereby heat is 7 r aocaass supplied to the thermomatiwhile heat is supplied heating means to cause the average temperatureof the control device to equal substantially the average temperature ofthe space.

18. In a heating system for a building, the combination of heating meansfor the building,

a control device subject to the same general at- 4 mospheric conditionsas the building and capable of retaining heat, heating means for thecontrol device, and control means responsive to the temperature of thecontrol device for controlling both of said heating means, thearrangement being such that the efiects of the heating means of thebuilding and the control device are proportioned according to the heatloss character- 25 istics of the building and the control device.

19. In a heating system for a building, the combination'oi heating meansforthe building, a'control device constructed to absorb and radiate heatand subject to the same general atmospheric conditions as the building,heating means for-the control device, the effect ofthe heating means forthe building and the control device being proportioned according to theheat loss characteristics of the building and the control device,

and means responsive to the temperature of the control device forcontrolling both heating means.

20. In a heating system for a building, the combination oi heating meansfor the building, a control device subject to the same generalatmospheric conditions as the building and having means for storingheat, heating means for the control device, the-efiect of the heatingmeans for the building and the control device being proportionedaccording to the heat losses from the building and the control device,and means responsive to the temperature of the control device forcontrolling both heating means.

21. In a heating system for a building, the combination of heating meansi'or' the building, a control device subject to the same generalatmospheric conditions as the building and hav- --ing a mass fordetermining the heat'loss charvice for controlling acteristic of thecontrol device, heating means for the control device, the effect of theheating means for the building and the control device being proportionedaccording to the heat losses from the building and the control device,and means responsive to the temperature of the control device forcontrolling both heating means.

22. In a heating system for a building, the combination of .heatingmeans for a building, a control device of substantial mass subject tothe same general atmospheric conditions as the building, heating meansfor the control device, means responsive to the temperature of thecontrol deboth heating means; and means for adjusting at least one oithe heating means to cause the heat inputs to the building and thecontrol device to be proportioned to the heat losses of the building andthe control device.

metallic, block, a thermostat responsive tothe temperature thereof,means for heating the mecontrol the heating apparatus and heating meansl to supply heat in accordance with the temperature of the heatconductive means.

25. A device of the class described, including a building to be heated,acontrol station of substantial mass outside of the building and of avolume extremely less than the volume of the building and subject tometeorological conditions which also ailfect the building, heating meansfor supplying heat to the building and to the control station inproportion to their relative heat losses, and a control deviceresponsive to the temperature of the control station for controlling theoperation of said heating means.

26. In a temperature control system for a building having a plurality ofcompartments, the

source of heat and the heating means, the central source of heat and theheating means being so proportioned with respect to each other that thethermostatic means maintains a substantially constant average temperatmewithin the building.

27. In a temperature control system for a building having a plurality ofcompartments, the combination of a central source of conditioning fluid,means for conveying the conditioning fluid. to the various compartmentsto cause conditioning of the compartments, a controller locatedoutside-oi the building and subject to the same ambient conditions asthe building, conditioning means for the controller, thermostatic meansresponsive to the temperature of the controller for controlling thecentral source of conditioning fluid and theconditioning means, andmeans for adjusting the eiiect oi the controller conditioning meanswhereby the thermostatic means operates to maintain a substantiallyconstant average temperature within the building.-

28. A system of heat control including a building to be heated;electrical y oper ble means i'or controlling heat to the building; acontrol device outside or the building subject to the same ambientconditions as the building and includ ing heat absorbing and radiatingmeans. temperature responsive means and an electric heater havingsumcient capacity to raise the temperature oi! the control device to agiven value in cold weather; means controlled by the temperatureresponsive means to control said heat controlling means and saidelectric heater; 'and means adjustable for varying the heat output ofthe electric heater to cause the heat inputs to the control device andthe buildirm to be to the heat losses therefrom.

29. A building exposed to outdoor conditions and means to vary its 7s anenclosure exposed to the same outdoor atmospheric conditions and meansto vary its temperature, and means responsive to the temperature of theenclosure constituting the sole control of both of thetemperaturevarying means and arranged to maintain substantially constanttemperatures in said building and enclosure.

30. In a device of the class described the combination with a building,of a mass located outside of the building, means for heating thebuilding, means for heating the mass and having sufficient capacity toheat said mass to a predetermined temperature for all normal outsidetemperature conditions, and a thermostatic element actuated by thetemperature of the mass when the temperature of the mass is below saidpredetermined temperature for simultaneously operating the two heatingmeans,

31. A temperature control system for a build ing, the rate of heat lossof which varies in accordance with changes in outdoor atmosphericconditions including temperature, wind and solar radiation, comprisingin combination, means for supplying heat to the building, a deviceoutside of the building, heating means to heat at least a portion ofsaid device and of suflicient capacity to raise the temperature of thedevice to a desired value in cold weather, and means including meanscontrolled by the heat supplied to said device and the heat loss fromsaid device for operating said heat supplying means for the building andthe heating means for the device to maintain the temperature of each atsubstantially constant values.

DANIEL G. TAYLOR.

